With an increase in the packing density of LSIs, the required linewidths of circuits included in semiconductor devices become finer year by year. To form a desired circuit pattern on a semiconductor device, a method is employed in which a high-precision original pattern (i.e., a mask, or also particularly called reticle, which is used in a stepper or a scanner) formed on quartz is transferred to a wafer in a reduced manner by using a reduced-projection exposure apparatus. The high-precision original pattern is written by using an electron-beam writing apparatus, in which a so-called electron-beam lithography technique is employed.
A writing apparatus using multiple beams can provide significantly improved throughput, because it is capable of irradiating with more beams at a time than when writing with a single electron beam. In a multi-beam writing apparatus using a blanking aperture array (which is an exemplary multi-beam writing apparatus), for example, an electron beam emitted from an electron gun is passed through a shaping aperture array having a plurality of openings to form multiple beams (a plurality of electron beams). The multiple beams then pass through corresponding blankers in the blanking aperture array.
The blanking aperture array has electrode pairs configured to deflect individual beams, and each of the electrode pairs has an opening for beam passage between its electrodes. While one electrode of each electrode pair (blanker) is fixed at the ground potential, the other electrode is switched between the ground potential and another potential, and thus electron beams passing through are individually subjected to blanking deflection. Electron beams deflected by the blankers are blocked, whereas undeflected electron beams are applied onto a sample.
In conventional multi-beam writing apparatuses, if, for example, an aperture member is displaced in the height direction, tilted, or warped when mounted onto the apparatus, some of multiple beams formed by a shaping aperture array may fail to pass through openings in a blanking aperture array. As a result, a beam array to be formed into an image on the sample surface may be partially lost.